CVE-2021-34585

Name: CVE-2021-34585
Creator: NVD / NIST
Published: 2021-10-26T10:15:07.907+00:00
License: https://creativecommons.org/publicdomain/zero/1.0/

HIGHCVSS 7.5/10EPSS 0.90%

Last modified Jun 17, 2026

CVE-2021-34585 is a high-severity vulnerability rated 7.5/10 on the CVSS scale. In the CODESYS V2 web server prior to V1.1.9.22 crafted web server requests can trigger a parser error. Since the parser result is not checked under all conditions, a pointer dereference with an invalid address can occur. EPSS estimates a 0.90% chance of exploitation in the next 30 days.

Description

In the CODESYS V2 web server prior to V1.1.9.22 crafted web server requests can trigger a parser error. Since the parser result is not checked under all conditions, a pointer dereference with an invalid address can occur. This leads to a denial of service situation.

Metrics

CVSS 3.1

7.5/10

CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H

EPSS Probability

0.90%

55.0th percentile

Probability of exploitation in the next 30 days. Learn more

Weakness Enumeration

CWE-252

Affected Software

Vendor	Product	Versions
Wago	750-823 Firmware	< fw10
Wago	750-829 Firmware	< fw17
Wago	750-831 Firmware	< fw17
Wago	750-832 Firmware	< fw10
Wago	750-852 Firmware	< fw17
Wago	750-862 Firmware	< fw10
Wago	750-880 Firmware	< fw17
Wago	750-881 Firmware	< fw17
Wago	750-882 Firmware	< fw17
Wago	750-885 Firmware	< fw17
Wago	750-889 Firmware	< fw17
Wago	750-890 Firmware	< fw10
Wago	750-891 Firmware	< fw10
Wago	750-893 Firmware	< fw10
Wago	750-8202 Firmware	< fw20
Wago	750-8203 Firmware	< fw20
Wago	750-8204 Firmware	< fw20
Wago	750-8206 Firmware	< fw20
Wago	750-8207 Firmware	< fw20
Wago	750-8208 Firmware	< fw20
Wago	750-8210 Firmware	< fw20
Wago	750-8211 Firmware	< fw20
Wago	750-8212 Firmware	< fw20
Wago	750-8213 Firmware	< fw20
Wago	750-8214 Firmware	< fw20
Wago	750-8216 Firmware	< fw20
Wago	750-8217 Firmware	< fw20
Codesys	Codesys	< 1.1.9.22

References

https://customers.codesys.com/index.php?eID=dumpFile&t=f&f=16876&token=a3f1d937f95e7034879f4f2ea8e5a99b168256a7&download=Vendor Advisory
https://www.tenable.com/security/research/tra-2021-47Exploit, Third Party Advisory
https://customers.codesys.com/index.php?eID=dumpFile&t=f&f=16876&token=a3f1d937f95e7034879f4f2ea8e5a99b168256a7&download=Vendor Advisory
https://www.tenable.com/security/research/tra-2021-47Exploit, Third Party Advisory

Timeline

Published: Oct 26, 2021
Last Modified: Jun 17, 2026
Status: Analyzed

Frequently Asked Questions

What is CVE-2021-34585?

How severe is CVE-2021-34585?

CVE-2021-34585 has a CVSS score of 7.5/10 (HIGH severity). The EPSS model estimates a 0.90% probability of exploitation in the next 30 days.

How do I fix CVE-2021-34585?

Check the vendor references and advisories linked above for patched versions and mitigation guidance. You can also run a Strix scan to test if your systems are affected.

Are you affected by CVE-2021-34585?

Run a free Strix scan to check your systems for this vulnerability.

Scan your code now

Source: NVD / NIST